Enhancement of methanol production by electronic interaction of La-Zn in plasma catalytic direct oxidation of methane at mild condition

The plasma catalytic direct oxidation of methane into the value-added chemical methanol over LaZnAl catalyst was investigated under mild condition. The synergistic effect between plasma and the LaZnAl catalyst was achieved. The electronic interaction of La-Zn facilitated the formation of oxygen vacancies, and promoted the utilization of the plasmaactivated O radicals, and enhanced the formation rate of the key intermediate CH3O species, thereby leading to low apparent activation energies for methane conversion and methanol production. The interaction of La-Zn species resulted in a significantly enhanced contribution of 89.6% to methanol formation, whereas the contribution of Zn alone was only 23.7%, and that of La was even negative (-32.9%). Consequently, methanol production was markedly improved and a methanol selectivity of 40.9% was achieved over the LaZnAl catalyst, compared to 26.7% for ZnAl and 14.5% for LaAl.